Obligate weed: A weed species that exclusively grows in cropped or cultivated land.
Facultative weed: A weed that can grow both in cropped fields and in wild or uncultivated lands.
Objectionable weed: A problematic weed whose seeds, once mixed with crop seeds, are very difficult to remove or control.
Noxious weed: An undesirable and troublesome weed that is particularly difficult to manage or eradicate.
Satellite weed: A weed that becomes an established and integral component of a crop ecosystem over time.
Parasitic weed: A weed that derives nutrients and growth support by attaching itself to a host plant.